1. Field of the Invention
The present invention relates to a mounting mechanism of a metal plate on a printed board, and in particular to a mounting mechanism of a metal plate on a printed board where mounting strength of a metal plate to be soldered on a land has been improved.
2. Description of the Related Art
One example of a conventional mounting mechanism of a metal plate on such a printed board will be explained with reference to FIGS. 3 and 4.
In these figures, reference numeral 1 denotes a printed board or printed wiring board. A copper foil (hereinafter, referred to as land) 2 is disposed on an surface of the printed board 1, a joining or bonding portion 3a of a strip-shape nickel plate 3 which is narrower than the land 2 is overlapped on an upper face of the land 2, and the nickel plate 3 is soldered to the land 2 through reflow.
Therefore, a front end of the land 2 projects slightly from a front end of the joining portion 3a of the nickel plate 3, so that fillets 4 with a sectional configuration of almost triangle are formed between three sides of the joining portion 3a and a surface of the land 2 due to solder melted and flowed out when the soldering is made through the reflow, as shown in FIG. 4.
In a case that the above conventional mounting mechanism of a metal plate on a printed board is assembled in, for example, a portable or mobile telephone or the like, the mounting mechanism is not only required to be made small and light but also the soldering strength (peel strength) is required to be increased so as to endure the carrying of such a portable device.
However, in the mounting mechanism of a metal plate on the printed board, the area of the land 2 is also reduced according to the requirements of the small sizing and the weight reduction, so that the joining area of the joining portion 3a of the nickel plate 3 is narrowed and reduced necessarily. Therefore, the joining strength between the land 2 and the nickel plate 3 is also lowered.
A technical problem to be solved occurs in order to achieve a mounting mechanism of a metal plate on a printed board where mounting strength of a metal plate can be enhanced without increasing a outer configuration or area of a land, and an object of the present invention is to solve this problem.
The present invention has been made to solve the above problem. According to a first aspect of the present invention, there is provided a mounting mechanism of a metal plate on a printed board where a metal plate connected with a terminal portion of a cell, part, or the like is joined to a land via solder, wherein a cut-out portion is provide at a joined portion of the metal plate which is joined to the land, and the total length of the fillets of the solder formed between the land and the joining portion is extended by the cut-out portion.
Thus, since the cut-out portion is provided in the joining portion of the metal plate connected to the land, and the total length of a fillet formed between the land and the joining portion is extended by the cut-out portion when the metal plate is soldered to the land, such an excellent effect can be obtained that the mounting strength of the metal plate to the land can be increased without increasing an outer area of the land, and size reduction and manufacturing cost reduction of a printed board can be achieved.
According to a second aspect of the invention, there is provided a mounting mechanism of a metal plate on a printed board according to the first aspect, wherein the cut-out portion provided in the metal plate is formed at a front end portion of the joining portion of the metal plate so as to have a U-shape opened towards a front edge.